US11994493B2 - Method for nondestructive assessment of steel - Google Patents
Method for nondestructive assessment of steel Download PDFInfo
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- US11994493B2 US11994493B2 US17/434,866 US202017434866A US11994493B2 US 11994493 B2 US11994493 B2 US 11994493B2 US 202017434866 A US202017434866 A US 202017434866A US 11994493 B2 US11994493 B2 US 11994493B2
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 111
- 239000010959 steel Substances 0.000 title claims abstract description 111
- 238000000034 method Methods 0.000 title claims abstract description 107
- 238000007689 inspection Methods 0.000 claims abstract description 278
- 230000035515 penetration Effects 0.000 claims abstract description 75
- 238000004381 surface treatment Methods 0.000 claims abstract description 60
- 230000001066 destructive effect Effects 0.000 claims abstract description 58
- 230000035699 permeability Effects 0.000 claims abstract description 44
- 230000008859 change Effects 0.000 claims abstract description 22
- 238000011156 evaluation Methods 0.000 claims description 81
- 238000011282 treatment Methods 0.000 claims description 68
- 239000000463 material Substances 0.000 claims description 56
- 230000002950 deficient Effects 0.000 claims description 55
- 238000005480 shot peening Methods 0.000 claims description 44
- 238000005255 carburizing Methods 0.000 claims description 30
- 238000010791 quenching Methods 0.000 claims description 26
- 230000000171 quenching effect Effects 0.000 claims description 26
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 20
- 229910052799 carbon Inorganic materials 0.000 claims description 20
- 230000007547 defect Effects 0.000 claims description 14
- 238000005496 tempering Methods 0.000 claims description 10
- 238000002360 preparation method Methods 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000004033 plastic Substances 0.000 claims description 7
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- 238000000137 annealing Methods 0.000 claims description 5
- 238000005121 nitriding Methods 0.000 claims description 5
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- 230000004044 response Effects 0.000 claims description 4
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- 239000012925 reference material Substances 0.000 description 22
- 238000001303 quality assessment method Methods 0.000 description 9
- 238000005259 measurement Methods 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 238000003754 machining Methods 0.000 description 5
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- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229910001566 austenite Inorganic materials 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- VNTLIPZTSJSULJ-UHFFFAOYSA-N chromium molybdenum Chemical compound [Cr].[Mo] VNTLIPZTSJSULJ-UHFFFAOYSA-N 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
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Images
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/023—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance where the material is placed in the field of a coil
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
- G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
- G01N27/9006—Details, e.g. in the structure or functioning of sensors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/80—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating mechanical hardness, e.g. by investigating saturation or remanence of ferromagnetic material
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
- G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
- G01N27/9046—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents by analysing electrical signals
Definitions
- the present invention relates to a method for non-destructive inspection of steel.
- non-destructive inspection method in which alternating current is passed through a coil disposed on the surface of steel which is an object under inspection, the impedance of the coil is measured, and thereby the residual stress distribution in the object under inspection which has been subjected to a shot peening treatment is measured (see Patent Literature 1).
- This non-destructive inspection method involves evaluating the object under inspection by: pre-acquiring data relating to the impedances of a plurality of samples (pieces of steel having been subjected to a shot peening treatment) in which residual stress in different states is generated; and comparing the acquired data and data relating to the impedance of the object under inspection.
- the above non-destructive inspection method is capable of measuring the state of residual stress generated in steel having been subjected to a shot peening treatment
- the above non-destructive inspection method is not capable of determining whether, for example, the carbon content of the steel having been subjected to a shot peening treatment is normal or not. Therefore, for example, in a case where a shot peening step was carried out after a carburizing and quenching step, it is not possible to determine whether a defect occurred in the carburizing and quenching step or in the shot peening step.
- the foregoing non-destructive inspection method has an issue in that, even if the steel (object under inspection) is determined to be a defective material, it is not possible to determine in which step the defect occurred; therefore, the foregoing non-destructive inspection method has room for improvement in accuracy of evaluation of the surface condition of the object under inspection.
- An aspect of the present invention was made in view of the above issue, and an object thereof is to provide a method for non-destructive inspection of steel which is capable of evaluating, with high accuracy, the surface condition of an object under inspection.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention which was made in order to attain the above object, includes a preparation step, a placing step, an eddy current generating step, a frequency changing step, an impedance calculating step, and an evaluation step.
- the preparation step involves preparing a non-destructive inspection apparatus which includes a variable frequency circuit and a coil.
- the variable frequency circuit is capable of changing the frequency of alternating current.
- the coil is capable of inducing an AC magnetic field in response to alternating current.
- the placing step involves placing an object under inspection so that the AC magnetic field induced by the coil penetrates into the object under inspection.
- the object under inspection is steel which has been subjected to one or more surface treatments.
- the eddy current generating step involves generating eddy current in the object under inspection by allowing the AC magnetic field to penetrate into the object under inspection.
- the frequency changing step involves continuously changing the penetration depth of the AC magnetic field in the object under inspection by causing the variable frequency circuit to continuously change the frequency of the alternating current from a low frequency to a high frequency.
- the impedance calculating step involves calculating the value of impedance at each penetration depth in the object under inspection on the basis of the potential difference between opposite ends of the coil and the value of electric current passing through the coil.
- the evaluation step involves evaluating the state of the one or more surface treatments of the object under inspection by (a) calculating the ratio between the value of impedance at each penetration depth in the object under inspection calculated in the impedance calculating step and the value of impedance at a corresponding penetration depth in steel which has not been subjected to the one or more surface treatments and (b) identifying one or more causes of a change in magnetic permeability of the object under inspection on the basis of the ratio thus calculated.
- the one or more causes of the change in magnetic permeability include, for example, the carbon content or nitrogen content of the object under inspection, the size and shape of the object under inspection, the hardness of the object under inspection, and the like.
- a method for non-destructive inspection of steel in accordance with the present invention makes it possible to evaluate, with high accuracy, the state of surface treatment(s) of an object under inspection by identifying a cause of a change in magnetic permeability of the object under inspection.
- FIG. 1 is a circuit diagram of a non-destructive inspection apparatus in accordance with Embodiment 1 of the present invention.
- FIG. 2 schematically illustrates an AC magnetic field generated in a coil in accordance with Embodiment 1.
- FIG. 3 is a flowchart illustrating a method for non-destructive inspection of steel in accordance with Embodiment 1.
- FIG. 4 is a flowchart illustrating a flow of a production process in accordance with Embodiment 1.
- FIG. 5 is a flowchart illustrating a flow of a setting step in accordance with Embodiment 1.
- FIG. 6 is a flowchart illustrating a flow of an evaluation step in accordance with Embodiment 1.
- FIG. 7 is a chart showing examples of the result of impedance ratio calculation in the evaluation step in accordance with Embodiment 1.
- (b) of FIG. 7 illustrates an example of content displayed on a display device in a notifying step in accordance with Embodiment 1.
- FIG. 8 is a chart showing the manner in which the magnetic permeability of steel having been subjected to a surface treatment in accordance with Embodiment 1 changes.
- FIG. 9 is a chart showing examples of the result of impedance ratio calculation in accordance with Variation 1 of Embodiment 1.
- FIG. 10 is a flowchart illustrating a flow of an evaluation step in accordance with Embodiment 2 of the present invention.
- FIG. 11 is a chart showing examples of the result of impedance ratio calculation in the evaluation step in accordance with Embodiment 2.
- (b) of FIG. 11 illustrates an example of content displayed on a display device in a notifying step in accordance with Embodiment 2.
- FIG. 12 is a flowchart illustrating a flow of an evaluation step in accordance with Embodiment 3 of the present invention.
- FIG. 13 is a chart showing examples of the result of impedance ratio calculation in the evaluation step in accordance with Embodiment 3.
- (b) of FIG. 13 illustrates an example of content displayed on a display device in a notifying step in accordance with Embodiment 3.
- a non-destructive inspection apparatus 1 in accordance with Embodiment includes an oscillator 10 , a detector 20 , and a measurement instrument 30 .
- the oscillator 10 includes an alternating current source 11 and a variable frequency circuit 12 .
- the variable frequency circuit 12 is connected to the alternating current source 11 , and changes the frequency of alternating current outputted from the alternating current source 11 .
- the detector 20 includes a coil 21 (described later). An end (point A in FIG. 1 ) of the coil 21 is connected to the alternating current source 11 , and is supplied with alternating current outputted from the alternating current source 11 . The other end (point B in FIG. 1 ) of the coil 21 is connected to an I/V conversion circuit 34 (described later).
- the detector 20 is used to carry out evaluation (which is a quality assessment in Embodiment 1) of an object under inspection M (described later) (see FIG. 3 ). Note that the circuit symbol enclosed by dashed line in FIG. 1 , indicating the coil 21 , represents the electrical equivalent circuit of the coil 21 .
- the coil 21 consists of a plurality of conducting wire rods wound into a cylinder.
- use of a bundle of thin conducting wires, which is like a single wire, as a wire rod makes it possible to raise the resonant frequency of the coil 21 .
- the coil 21 may be one obtained by winding a wire rod around a hollow cylindrical core (cored coil).
- the wire rod may be a single conducting wire.
- the coil 21 of Embodiment 1 was prepared by the following method: first, a wire rod, obtained by interlacing and twisting several hundreds of enameled copper wires, was wound around a resin cylinder, then the wound wire rod was bonded with epoxy resin, and the cylinder was removed.
- the coil 21 can also be produced by some other method such as a method by which a wire rod covered with a thermosetting resin is coiled and then dried with hot air or in a drying furnace etc. to fix the wire rod so as to maintain the shape of the rod.
- the method of producing the coil 21 is not particularly limited, provided that the wire rod maintains the shape of the coil as such.
- the measurement instrument 30 includes an amplifier circuit 31 , an absolute value circuit 32 , a low-pass filter (LPF) 33 , an I/V conversion circuit 34 , an absolute value circuit 35 , an LPF 36 , a control section 37 , and a display device 38 .
- the measurement instrument 30 serves to measure changes in the value of impedance of the coil 21 on the basis of a signal indicating electrical properties of alternating current passing through the coil 21 .
- the amplifier circuit 31 has one end (the left end in FIG. 1 ) connected to the opposite ends (points A and B in FIG. 1 ) of the coil 21 , and has the other end (the right end in FIG. 1 ) connected to the absolute value circuit 32 .
- a signal indicating the potential difference between the opposite ends of the coil 21 is inputted.
- the signal inputted into the amplifier circuit 31 is amplified and inputted into the absolute value circuit 32 .
- the absolute value circuit 32 is a full-wave rectifier circuit.
- the potential difference signal inputted into the absolute value circuit 32 is full-wave rectified and then converted into direct current by the LPF 33 .
- the potential difference signal converted by the LPF 33 is inputted into the control section 37 .
- the I/V conversion circuit 34 is connected to the other end (point B in FIG. 1 ) of the coil 21 .
- a signal indicating the value of electric current passed through the coli 21 is inputted into the I/V conversion circuit 34 , and converted into a signal indicating potential difference. Then, the signal indicating the potential difference is full-wave rectified by the absolute value circuit 35 , and then converted into direct current by the LPF 36 .
- the signal converted by the LPF 36 is inputted into the control section 37 .
- the control section 37 includes a microprocessor, an interface circuit, a memory, programs for causing these members to operate, and the like (which are not illustrated).
- the control section 37 is connected to the variable frequency circuit 12 , the LPF 33 , and the LPF 36 .
- the following signals indicating the electrical properties of the coil 21 are inputted: a signal indicating the frequency of alternating current passing through the coil 21 ; a signal indicating the value of electric current corresponding to the frequency; and a signal indicating the potential difference.
- the control section 37 calculates the value of impedance at each frequency on the basis of the signals indicating the electrical properties of the coil 21 .
- control section 37 has the function of outputting, to the variable frequency circuit 12 , a signal that changes frequency automatically and continuously.
- the frequency is changed via the variable frequency circuit 12 in response to control output from the control section 37 under the conditions in which steel (object under inspection M) is disposed within the coil 21 (see FIG. 2 ).
- the frequency of the alternating current may be changed manually.
- control section 37 calculates a value Z 2 of the impedance at each frequency as the frequency continuously changes, and calculates an impedance ratio ⁇ 2 (Z 2 /Z 0 ), i.e., the ratio between the calculated value Z 2 of the impedance and a value Z 0 of the impedance of steel which has not been subjected to a predetermined surface treatment (such steel is “reference material”). Furthermore, the control section calculates an impedance ratio ⁇ 1 (Z 1 /Z 0 ), i.e., the ratio between a value Z 1 of impedance at each penetration depth in a case of a non-defective material and the impedance Z 0 of the steel which has not been subjected to the surface treatment. Then, the control section 37 compares the impedance ratio ⁇ 2 of the object under inspection M and the impedance ratio ⁇ 1 of the non-defective material, thereby carrying out a quality assessment of the surface condition of the object under inspection M.
- the display device 38 is a device to display, in a notifying step (S 8 ) (described later), the results of evaluation (results of quality assessment) carried out by the control section 37 , as illustrated in (b) of FIG. 7 . As illustrated in (a) of FIG. 7 , the display device 38 not only displays the results of the quality assessment on the object under inspection M but also displays a chart showing the relationship between the impedance ratio ⁇ 2 of the object under inspection M and penetration depth.
- alternating current is applied to the coil 21 of the non-destructive inspection apparatus 1 from the alternating current source 11 .
- an AC magnetic field induced by the coil 21 penetrates into the object under inspection M disposed within the coil 21 (describe later) (see FIG. 2 ). This generates eddy current in the object under inspection M.
- the control section 37 outputs a control signal to the variable frequency circuit 12 , thereby making it possible to continuously change the frequency of alternating current from a low frequency to a high frequency. Since the variable frequency circuit 12 continuously changes the frequency of alternating current, it is possible to continuously change the penetration depth of the AC magnetic field in the object under inspection M. Specifically, the frequency of alternating current is, for example, changed from a frequency as low as about 10 kHz to a frequency as high as about 20 MHz. With this, the penetration depth of the AC magnetic field in the object under inspection M is changed from 0 ⁇ m to 150 ⁇ m.
- ⁇ represents penetration depth [m]
- f represents the frequency of alternating current [Hz]
- ⁇ represents the electrical conductivity [S/m] of the object under inspection M
- p represents the magnetic permeability [H/m] of the object under inspection M.
- the control section 37 calculates the value of impedance at each penetration depth in the object under inspection M by: continuously changing the penetration depth of the AC magnetic field in the object under inspection M; and calculating the ratio between the potential difference between the opposite ends of the coil 21 and the value of electric current passing through the coil 21 .
- This value of impedance changes with, for example, changes in the magnetic permeability of steel having been subjected to a surface treatment.
- the magnetic permeability of the object under inspection M changes in relation to various parameters such as the carbon content or nitrogen content of the object under inspection M, the magnitude and direction of elastic strain in the object under inspection M, the magnitude of plastic strain in the object under inspection M, arrangement of atoms (phase transformation) in the object under inspection M, size and shape of the object under inspection M, and hardness of the object under inspection M.
- the relationship between the above parameters and the magnetic permeability is used to carry out various evaluations on the object under inspection M which is steel having been subjected to a surface treatment (see FIG. 3 ).
- a casting step (S 11 ) is carried out, and thereafter a machining step (S 12 ) such as cutting and processing is carried out.
- a machining step (S 12 ) such as cutting and processing is carried out.
- the steel is cut and processed into a desired shape (cylindrical shape, gear shape, or the like). Note that the type of machining can be changed as appropriate.
- a carburizing and quenching step (S 13 ) is carried out.
- steel is subjected to a carburizing and quenching treatment, and thereby the amount of carbon in the surface of the steel increases and the magnetic permeability of the steel decreases.
- the amount of carbon is merely an example of a cause of a change in magnetic permeability, and the magnetic permeability of the object under inspection M changes with the foregoing plurality of parameters.
- a shot peening step (S 14 ) is carried out.
- a shot peening apparatus (not illustrated) is used to project a shot material in the form of small spheres to the surface of the steel, thereby giving a modification to the surface of the steel.
- the magnetic permeability of the surface of the steel has been increased as compared to that before the shot peening.
- a finishing step (S 15 ) is carried out.
- the steel is subjected to finishing such as, for example, brushing, buffing, and/or barreling, as appropriate.
- a preparation step (S 1 ) involving preparing steel, which is an object under inspection M, and preparing the foregoing non-destructive inspection apparatus 1 is carried out.
- the steel, which is the object under inspection M is intended to be, for example, steel for use in a component (such as gear wheel or gear) for automobiles, aircrafts, construction equipment, or the like or others such as springs, molds, or tools.
- Embodiment 1 steel which has been subjected to a carburizing and quenching treatment in the carburizing and quenching step (S 13 ) and then subjected to a shot peening treatment in the shot peening step (S 14 ) is used as the object under inspection M.
- a material for the steel, which is the object under inspection M is, for example, a chromium-molybdenum steel (JIS standard: SCM420).
- the shape of the steel, which is the object under inspection M is a cylindrical shape obtained by machining the steel into the cylindrical shape in the machining step (S 12 ).
- a setting step (S 2 ) is carried out.
- the setting step (S 2 ) several steps are carried out in the order shown in the flowchart of FIG. 5 . Note that the flowchart shown in FIG. 5 is an example, and this does not imply any limitation.
- steel having not been subjected to a surface treatment such steel is “reference material”
- the reference material is placed at the center of a circular cross section of the coil 21 within the coil 21 in the cylindrical shape, and brought into conditions in which an AC magnetic field induced by the coil 21 is capable of penetrating into the steel having not been subjected to a surface treatment.
- conditions for measurement such as the position in which the reference material is placed and the range of the frequency of AC magnetic field passed through the coil 21 .
- conditions for measurement under which evaluation of the state of the surface treatment of the object under inspection M can be appropriately carried out are set in consideration of the relationship between the foregoing parameters and magnetic permeability.
- the AC magnetic field is allowed to penetrate into the reference material and the frequency of alternating current is continuously changed by the variable frequency circuit 12 , thereby continuously changing the penetration depth of the AC magnetic field in the reference material.
- the value Z 0 of impedance at each penetration depth in the reference material is measured (S 23 ), and the measured value Z 0 of impedance at each penetration depth in the reference material is stored in a database (not illustrated) (S 24 ).
- the database may have pre-stored therein data relating to the values Z 0 of impedance of reference materials subjected to various surface treatments, such as, for example, a shot peening treatment, a quenching treatment, a nitriding treatment, a carburizing treatment, a tempering treatment, an annealing treatment, a surface fabrication treatment, a polishing treatment, and/or a tempering treatment.
- various surface treatments such as, for example, a shot peening treatment, a quenching treatment, a nitriding treatment, a carburizing treatment, a tempering treatment, an annealing treatment, a surface fabrication treatment, a polishing treatment, and/or a tempering treatment.
- a method of assessment for use in an evaluation step (S 7 ) (described later) is selected (S 25 ).
- One method of assessment is selected from the three methods of assessment.
- non-defective material At least one piece of steel which has been subjected to a surface treatment in a good manner (non-defective material) is subjected to the same steps as S 21 to S 24 .
- the impedance value Z 1 of the non-defective material is measured in this manner, and data relating to this impedance value Z 1 is stored in the database.
- a threshold range for use in the method of assessment selected in S 25 is set (S 26 ).
- the setting step (S 2 ) ends.
- a placing step (S 3 ) to an evaluation step (S 7 ) are preferably carried out immediately after the setting step (S 2 ). This is because this makes it possible to reduce the influence of disturbance factors such as surrounding temperature, and thus possible to improve the accuracy of the evaluation.
- the process returns to FIG. 3 , and the placing step (S 3 ) involving placing the steel, which is the object under inspection M, is carried out.
- the steel, which is the object under inspection M is placed at the center of a circular cross section of the coil 21 within the coil 21 in the cylindrical shape, and brought into conditions in which an AC magnetic field induced by the coil 21 is capable of penetrating into the object under inspection M.
- a method for placing the member is not limited as such, provided that the AC magnetic field in the coil 21 penetrates into the object under inspection M.
- the object under inspection M may alternatively be placed so as to face the coil 21 .
- an eddy current generating step (S 4 ) involving generating eddy current in the object under inspection M is carried out.
- the control section 37 operates the alternating current source 11 via the variable frequency circuit 12 .
- an AC magnetic field is induced in the coil 21 (see FIG. 2 ).
- Eddy current is generated in the object under inspection M by allowing the AC magnetic field to penetrate into the object under inspection M.
- a frequency changing step (S 5 ) involving continuously changing the penetration depth of the AC magnetic field in the object under inspection M is carried out.
- the control section 37 outputs a control signal to the variable frequency circuit 12 , thereby continuously changing the frequency of alternating current outputted from the alternating current source 11 .
- the penetration depth of the AC magnetic field in the object under inspection M continuously changes.
- the penetration depth of the AC magnetic field in the object under inspection M differs depending on the makeup of the interior portion of the object under inspection M even if the same AC magnetic field is applied to the object under inspection M.
- Embodiment 1 the quality of the surface condition of the object under inspection M was examined while changing the penetration depth of the AC magnetic field in the object under inspection M from 0 ⁇ m to 150 ⁇ m (see (a) of FIG. 7 and FIG. 8 ).
- an impedance calculating step (S 6 ) involving calculating the value Z 2 of the impedance at each penetration depth in the object under inspection M is carried out.
- the control section 37 calculates the value Z 2 of the impedance on the basis of the potential difference between the opposite ends (point A and point B in FIG. 1 ) of the coil 21 and the value of electric current passing through the coil 21 .
- the evaluation step (S 7 ) involving examining the quality of the surface condition of the object under inspection M is carried out. Specifically, several steps are carried out in the order shown in the flowchart of FIG. 6 . Note that the flowchart shown in FIG. 6 is an example, and does not imply any limitation.
- the control section 37 calculates an impedance ratio ⁇ 2 (Z 2 /Z 0 ), which is the ratio between the value Z 2 of the impedance at each penetration depth in the object under inspection M calculated in the impedance calculating step (S 6 ) and the value Z 0 of the impedance at a corresponding penetration depth in the steel having not been subjected to a surface treatment (such steel is “reference material”) measured in the setting step (S 2 ). Then, whether the calculated impedance ratio ⁇ 2 of the object under inspection M is within the threshold range or not is determined (S 31 ). It is noted here that, with regard to the threshold range, the data set in the setting step (S 2 ) is used.
- the control section 37 determines the object under inspection M to be a non-defective material (S 32 ). On the contrary, in a case where the impedance ratio ⁇ 2 of the object under inspection M is outside the threshold range (NO in S 31 ), the control section 37 determines the object under inspection M to be a defective material (S 33 ).
- a notifying step (S 8 ) involving providing a notification indicative of whether the object under inspection M is a non-defective material or a defective material is carried out.
- the display device 38 displays whether the object under inspection M is a non-defective material or not.
- the display device 38 displays a chart in which the penetration depth is plotted on the horizontal axis and the impedance ratio ⁇ 2 of the object under inspection M is plotted on the vertical axis, as shown in (a) of FIG. 7 and FIG. 8 .
- the display device 38 also displays the results of assessment of the quality, as shown in (b) of FIG. 7 .
- the number of objects under inspection M measured is seven
- six of the seven objects under inspection M were determined to be non-defective materials
- one of the seven objects under inspection M was determined to be a defective material.
- the number of set points indicates that the impedance ratio ⁇ 2 was calculated at 151 penetration depths between 0 ⁇ m and 150 ⁇ m.
- FIG. 8 is a chart showing the manner in which the magnetic permeability of steel subjected to a surface treatment changes.
- a carburizing and quenching treatment in the carburizing and quenching step (S 13 )
- the carbon content in the surface of the steel increases.
- magnetic permeability decreases. Due to such an influence of the carburization, after the carburizing and quenching treatment, the impedance ratio ⁇ 2 of the object under inspection M has decreased as compared to that before the carburizing and quenching treatment (see circles in FIG. 8 ).
- the surface of the steel is modified and thereby the magnetic permeability of the steel increases. Due to such an influence of the shot peening (SP), after the shot peening treatment, the impedance ratio ⁇ 2 of the object under inspection M has increased as compared to that before the shot peening treatment (see squares in FIG. 8 ).
- the degree of shot peening e.g., the particle size of the shot material projected to the surface of the steel in shot peening is increased, the magnetic permeability of the surface of the steel becomes even greater due to the influence of SP (see lozenges in FIG. 8 ).
- the carbon content of the object under inspection M is small and a defect is determined to have occurred in the carburizing and quenching step (S 13 ).
- the magnetic permeability of the object under inspection M has been determined to be less than that of the non-defective material, it is determined that a defect occurred in the shot peening step (S 14 ) and the magnetic permeability was not increased to a sufficient extent.
- the non-destructive inspection apparatus 1 With the foregoing method for non-destructive inspection of steel in accordance with Embodiment 1, the non-destructive inspection apparatus 1 generates eddy current in an object under inspection M and then continuously changes the penetration depth of AC magnetic field in the object under inspection M, thereby making it possible to calculate an impedance ratio ⁇ 2 , which is the ratio between the value Z 2 of impedance at each penetration depth in the object under inspection M calculated in the impedance calculating step (S 6 ) and the value Z 0 of impedance at a corresponding penetration depth in steel having not been subjected to a surface treatment (such steel is “reference material”). It is further possible, on the basis of the result of impedance ratio ⁇ 2 calculation, to identify a cause of the change in the magnetic permeability of the object under inspection M and evaluate the state of the surface treatment of the object under inspection M with high accuracy.
- the impedance ratio ⁇ 1 of a non-defective material and the impedance ratio ⁇ 2 of a defective material it is possible to carry out evaluation (quality assessment) on the state of the surface treatment of the object under inspection M with high accuracy. Furthermore, by focusing on the amount of carbon which is one of the causes of a change in magnetic permeability of the object under inspection M, it is possible to determine whether the defect occurred in the carburizing step (S 13 ) or the shot peening step (S 14 ).
- evaluation can be carried out such that a method of assessment to be carried out in the evaluation step (S 7 ) is selected from the following three methods: (1) assessment based on area, (2) assessment based on peak, and (3) assessment based on integral, in the setting step (2).
- This makes it possible to improve the accuracy of the evaluation of the state of the surface treatment.
- good evaluation can be achieved by using the assessment based on area.
- the threshold range for use in the evaluation step (S 7 ) it is possible to adjust the accuracy of evaluation of the state of the surface treatment according to a user's need.
- evaluation can be carried out in the evaluation step (S 7 ) by a most appropriate method selected from the foregoing three methods of assessment (1) to (3), depending on the object under inspection M.
- This makes it possible to improve the accuracy of evaluation.
- the evaluation of the state of the surface treatment can be carried out reliably by employing evaluation using the distribution of the ratio (assessment based on area) of (1).
- Variation 1 differs from Embodiment 1 in that the steel having subjected to the carburizing and quenching step (S 13 ) shown in FIG. 4 is used as a reference material.
- FIG. 9 is a chart showing examples of the result of impedance ratio ⁇ 2 calculation in accordance with Variation 1.
- FIG. 9 shows that the impedance ratio ⁇ 2 of an object under inspection M calculated in the evaluation step (S 7 ) changes with changes in the particle size of the shot material used in the shot peening step (S 14 ). Specifically, as the particle size of the shot material is increased, the magnetic permeability of the object under inspection M increases and the impedance ratio ⁇ 2 of the object under inspection M becomes greater over a wide penetration depth range. In contrast, as the particle size of the shot material is reduced, the magnetic permeability of the object under inspection M decreases and the impedance ratio ⁇ 2 of the object under inspection M becomes smaller over a wide penetration depth range.
- At least one steel which has a desired size and shape is subjected to the same steps as the foregoing S 21 to S 24 .
- the impedance value Z 1 of the non-defective material is measured, and data relating to this impedance value Z 1 is stored in a database.
- the impedance ratio ⁇ 1 (Z 1 /Z 0 ) which is the ratio between the impedance value Z 0 at each penetration depth in the reference material and the impedance value Z 1 at a corresponding penetration depth in the non-defective material, is calculated, and this impedance ratio ⁇ 1 is stored in the database.
- the threshold range for use in the method of assessment selected in S 25 is set on the basis of the calculated impedance ratio ⁇ 1 of the non-defective material (S 26 ).
- the steps S 3 to S 6 in FIG. 3 are carried out in the same manner as described in Embodiment 1, thereby making it possible to evaluate the size and shape of the object under inspection M in the evaluation step S 7 .
- At least one steel which has a desired hardness is subjected to the same steps as the foregoing S 21 to S 24 .
- the impedance value Z 1 of the non-defective material is measured, and data relating to this impedance value Z 1 is stored in a database.
- the impedance ratio ⁇ 1 (Z 1 /Z 0 ) which is the ratio between the impedance value Z 0 at each penetration depth in the reference material and the impedance value Z 1 at a corresponding penetration depth in the non-defective material, is calculated, and this impedance ratio ⁇ 1 is stored in the database.
- the threshold range for use in the method of assessment selected in S 25 is set on the basis of the calculated impedance ratio ⁇ 1 of the non-defective material (S 26 ).
- the steps S 3 to S 6 in FIG. 3 are carried out in the same manner as described in Embodiment 1, thereby making it possible to evaluate the hardness of the object under inspection M in the evaluation step (S 7 ). With this, it is possible, when the hardness of the object under inspection M does not satisfy a desired condition, to determine the object under inspection M to be a defective material.
- the control section 37 determines whether or not the value of the impedance ratio ⁇ 2 of an object under inspection M at a specific penetration depth is within the threshold range (S 41 ). Specifically, evaluation (quality assessment in Embodiment 2) of the object under inspection M is carried out only with respect to a part (part enclosed by line in (a) of FIG. 11 ) of penetration depths at which the value of the impedance ratio ⁇ 2 of the object under inspection M peaks.
- the control section 37 determines the object under inspection M to be a non-defective material (S 42 ). On the contrary, in a case where the value of the impedance ratio ⁇ 2 of the object under inspection M is outside the threshold range (NO in S 41 ), the control section 37 determines the object under inspection M to be a defective material (S 43 ).
- the display device 38 displays the results of the quality assessment as illustrated in (b) of FIG. 11 .
- the following results of assessment are displayed: the number of objects under inspection M measured is seven, six of the seven objects under inspection M were determined to be non-defective materials, and one of the seven objects under inspection M was determined to be a defective material.
- the display also indicates that the evaluation was carried out only with respect to the range in which the penetration depth is 10 ⁇ m to 30 ⁇ m in the assessment based on peak.
- the method for non-destructive inspection of steel in accordance with Embodiment 2 also makes it possible to evaluate the state of a surface treatment of the object under inspection M with high accuracy, as with the case of Embodiment 1.
- assessment based on peak is used to carry out the evaluation step (S 7 a ) in Embodiment 2, and therefore it is possible to carry out evaluation with higher accuracy in a case where the difference between the impedance ratio ⁇ 1 of a non-defective material and the impedance ratio ⁇ 2 of a defective material is expected to be noticeable in the part where the impedance ratio ⁇ 2 peaks (at specific penetration depth(s)).
- evaluation (quality assessment) of the state of a surface treatment of an object under inspection M is carried out.
- the control section 37 determines whether or not the integral of the impedance ratio ⁇ 2 of the object under inspection M in a specific penetration depth range (see the area filled with black in (a) of FIG. 13 ) is within a threshold range (S 51 ). In a case where the integral of the impedance ratio ⁇ 2 of the object under inspection M in the specific penetration depth range is within the threshold range (YES in S 51 ), the control section 37 determines the object under inspection M to be a non-defective material (S 52 ).
- the control section 37 determines the object under inspection M to be a defective material (S 53 )
- the display device 38 displays the results of the quality assessment as illustrated in (b) of FIG. 13 .
- the display example shown in (b) of FIG. 13 indicates that evaluation was carried out by calculating the integral in a penetration depth range of 10 ⁇ m to 30 ⁇ m in the assessment based on integral.
- the method for non-destructive inspection of steel in accordance with Embodiment 3, as has been discussed, also makes it possible to evaluate the state of the surface treatment of the object under inspection M with high accuracy, as with the case of Embodiment 1.
- assessment based on area is used to carry out the evaluation step (S 7 b ) in Embodiment 3, and therefore it is possible, in a case where both the evaluation using the assessment based on area and the evaluation using assessment based on peak are difficult to carry out, to identify a slight difference between the impedance ratio ⁇ 1 of a non-defective material and the impedance ratio ⁇ 2 of a defective material by carrying out evaluation using the integral of the impedance ratio ⁇ 2 in a specific penetration depth range.
- a method most appropriate as the method of assessment for use in the evaluation step (S 7 ) is selected from the three methods of assessment ((1) assessment based on area, (2) assessment based on peak, and (3) assessment based on integral) in the setting step (S 2 ) and evaluation is carried out; however, this does not imply any limitation.
- two of the three methods of assessment (1) to (3) may be used or all the three methods of assessment (1) to (3) may be used.
- evaluation may be carried out by appropriately changing the method of assessment as the penetration depth changes.
- steel having been subjected to a shot peening treatment as a surface treatment is used as an object under inspection M; however, this does not imply any limitation.
- Steel having been subjected to some other surface treatment such as a quenching treatment, a nitriding treatment, a carburizing treatment, a tempering treatment, an annealing treatment, a surface fabrication treatment, a polishing treatment, or a tempering treatment can be used as an object under inspection M.
- the impedance ratio ⁇ 1 which is the ratio between the impedance value Z 0 of the reference material and the impedance value Z 1 of a non-defective material, in a database and appropriately setting a threshold range for use in evaluation in the setting step S 2 , it is possible to evaluate the state of the surface treatment of the object under inspection M with high accuracy.
- steel which was subjected to a carburizing and quenching treatment in the carburizing and quenching step (S 13 ) contains retained austenite.
- this undergoes phase transformation into martensite and the amount of the retained austenite decreases.
- the magnetic permeability of the steel increases.
- steel which was subjected to a shot peening treatment in the shot peening step (S 14 ) changes in magnetic permeability as the magnitude of plastic strain changes. Using such a relationship, it is also possible to evaluate the magnitude of plastic strain in the object under inspection M.
- steel which was subjected to a shot peening treatment in the shot peening step (S 14 ) changes in magnetic permeability as the magnitude and direction of elastic strain change. Using such a relationship, it is also possible to evaluate the magnitude and direction of elastic strain in the object under inspection M.
- the present invention is not limited to the foregoing embodiments, but can be altered within the scope of the claims.
- the present invention also encompasses, in its technical scope, any embodiment derived by combining technical means disclosed in differing embodiments.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention includes a preparation step, a placing step, an eddy current generating step, a frequency changing step, an impedance calculating step, and an evaluation step.
- the preparation step involves preparing a non-destructive inspection apparatus which includes a variable frequency circuit and a coil.
- the variable frequency circuit is capable of changing the frequency of alternating current.
- the coil is capable of inducing an AC magnetic field in response to alternating current.
- the placing step involves placing an object under inspection so that the AC magnetic field induced by the coil penetrates into the object under inspection.
- the object under inspection is steel which has been subjected to one or more surface treatments.
- the eddy current generating step involves generating eddy current in the object under inspection by allowing the AC magnetic field to penetrate into the object under inspection.
- the frequency changing step involves continuously changing the penetration depth of the AC magnetic field in the object under inspection by causing the variable frequency circuit to continuously change the frequency of the alternating current from a low frequency to a high frequency.
- the impedance calculating step involves calculating the value of impedance at each penetration depth in the object under inspection on the basis of the potential difference between opposite ends of the coil and the value of electric current passing through the coil.
- the evaluation step involves evaluating the state of the one or more surface treatments of the object under inspection by (a) calculating the ratio between the value of impedance at each penetration depth in the object under inspection calculated in the impedance calculating step and the value of impedance at a corresponding penetration depth in steel which has not been subjected to the one or more surface treatments and (b) identifying one or more causes of a change in magnetic permeability of the object under inspection on the basis of the ratio thus calculated.
- the one or more causes of the change in magnetic permeability include, for example, the carbon content or nitrogen content of the object under inspection, the size and shape of the object under inspection, the hardness of the object under inspection, and the like.
- the non-destructive inspection apparatus In the above method for non-destructive inspection of steel, the non-destructive inspection apparatus generates eddy current in the object under inspection and then the penetration depth of the AC magnetic field in the object under inspection is continuously changed, thereby making it possible to calculate the ratio (impedance ratio) between the value of impedance at each penetration depth in the object under inspection calculated in the impedance calculating step and the value of impedance at a corresponding penetration depth in steel which has not been subjected to the surface treatment. Then, it is possible to evaluate the state of the surface treatment(s) of the object under inspection by identifying cause(s) of a change in magnetic permeability of the object under inspection on the basis of the ratio thus calculated.
- the carbon content of the object under inspection is small and a defect is determined to have occurred in the carburizing and quenching step.
- the magnetic permeability of the object under inspection has been determined to be less than that of the non-defective material, it is determined that the defect occurred in the shot peening step and the magnetic permeability was not increased to a sufficient extent. In this way, it is possible to evaluate the state of the surface treatment(s) of the object under inspection with high accuracy.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention is configured such that the one or more causes of the change in magnetic permeability include a carbon content of the object under inspection, a magnitude and direction of elastic strain in the object under inspection, a magnitude of plastic strain in the object under inspection, and/or an arrangement of atoms in the object under inspection.
- the amount of carbon (carbon content) in the object under inspection is evaluated as a cause of a change in magnetic permeability, and thereby, with use of the difference in magnetic permeability between defective and non-defective materials resulting from the amounts of carbon, it is possible to determine that a defect occurred in, for example, the carburizing and quenching step. As such, it is possible to evaluate the object under inspection with higher accuracy.
- the amount of carbon in the object under inspection may be evaluated by calculating the carbon content of the object under inspection on the basis of the ratio.
- the amount of carbon in the object under inspection may be evaluated on the basis of the correlation between the ratio and the amount of carbon in the object under inspection.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention is configured such that the one or more surface treatments at least include a shot peening treatment, a quenching treatment, a nitriding treatment, a carburizing treatment, a tempering treatment, an annealing treatment, a surface fabrication treatment, a polishing treatment, or a tempering treatment.
- the above method for non-destructive inspection of steel makes it possible to determine whether or not at least the shot peening treatment, the quenching treatment, the nitriding treatment, the carburizing treatment, the tempering treatment, the annealing treatment, the surface fabrication treatment, the polishing treatment, or the tempering treatment has been carried out normally.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention is configured such that, in the evaluation step, the state of the one or more surface treatments of the object under inspection is evaluated by carrying out at least one of the following methods of assessment: (1) assessment of whether or not a distribution of the ratio is within a threshold range; (2) assessment of whether or not the ratio at a specific penetration depth is within a threshold range; and (3) assessment of whether or not an integral of the ratio in a specific penetration depth range is within a threshold range.
- the above method for non-destructive inspection of steel makes it possible, in the evaluation step, to carry out evaluation using the most appropriate method selected from the above three methods for assessment (1) to (3) according to the object under inspection, and thus possible to improve the accuracy of evaluation.
- the difference in impedance ratio between non-defective and defective materials is expected to occur in a wide range of penetration depths in the object under inspection M
- the difference in impedance ratio between non-defective and defective materials is expected to appear notably in a specific part of the penetration depths
- it is preferable to carry out evaluation using the ratio at a specific penetration depth(s) indicated in (2) In a case where the evaluation using the method of assessment (1) and the evaluation using the method of assessment (2) are both difficult, evaluation using the integral of the ratio in a specific penetration depth range makes it possible to identify a slight difference in ratio.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention includes a setting step which is carried out before the placing step, the setting step including selecting the at least one method of assessment which is to be carried out in the evaluation step and setting the threshold range(s) for use in the selected at least one method of assessment.
- the threshold range for use in the evaluation step is appropriately set in the setting step, thereby making it possible to adjust the accuracy of evaluation according to a user's need.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention is configured such that, in the evaluation step, a size and shape of the object under inspection are evaluated as the state of the one or more surface treatments.
- the above method for non-destructive inspection of steel makes it possible to evaluate whether or not the object under inspection has a desired size and shape.
- a method for non-destructive inspection of steel in accordance with an aspect of the present invention is configured such that, in the evaluation step, a hardness of the object under inspection is evaluated as the state of the one or more surface treatments.
- the above method for non-destructive inspection of steel makes it possible to evaluate whether or not the object under inspection has a desired hardness.
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Abstract
Description
-
- Japanese Patent Application Publication, Tokukai, No. 2008-002973
-
- 1 non-destructive inspection apparatus
- 11 alternating current source
- 12 variable frequency circuit
- 21 coil
- 37 control section
- 38 display device
- M object under inspection
- S1 preparation step
- S2 setting step
- S3 placing step
- S4 eddy current generating step
- S5 frequency changing step
- S6 impedance calculating step
- S7, S7 a, S7 b evaluation step
- S8 notifying step
Claims (7)
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JP2019042972A JP7180461B2 (en) | 2019-03-08 | 2019-03-08 | Nondestructive inspection method for steel |
JP2019-042972 | 2019-03-08 | ||
PCT/JP2020/001548 WO2020183908A1 (en) | 2019-03-08 | 2020-01-17 | Method for nondestructive assessment of steel |
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US11994493B2 true US11994493B2 (en) | 2024-05-28 |
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Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4528856A (en) | 1984-01-17 | 1985-07-16 | Westinghouse Electric Corp. | Eddy current stress-strain gauge |
JPH05203503A (en) | 1991-11-27 | 1993-08-10 | Toyota Motor Corp | Apparatus for measuring residual stress distribution of steel |
EP0618445A2 (en) | 1993-04-02 | 1994-10-05 | Robert Bosch Gmbh | Method and probe for non-destructive surface examination of electrically conducting materials |
JPH0792140A (en) | 1993-09-27 | 1995-04-07 | Toyota Motor Corp | Method for evaluating fatigue strength of steel member |
JP2001082911A (en) | 1999-09-14 | 2001-03-30 | Mitsubishi Heavy Ind Ltd | Component inspection apparatus |
JP2007040865A (en) | 2005-08-04 | 2007-02-15 | Ntn Corp | Nondestructive measuring method for determining depth of hardened layer, unhardened state and foreign material |
US20080001609A1 (en) | 2006-06-22 | 2008-01-03 | Takashi Kojima | Nondestructive inspection method and apparatus for a surface processed by shot peening |
JP2010025746A (en) | 2008-07-18 | 2010-02-04 | Toyota Motor Corp | Quenching pattern inspecting method and device |
JP2011185623A (en) | 2010-03-05 | 2011-09-22 | Toyota Central R&D Labs Inc | Device for evaluation of surface treatment |
WO2012153862A1 (en) | 2011-05-10 | 2012-11-15 | Sintokogio, Ltd. | Surface property inspection device and surface property inspection method |
US20150083918A1 (en) | 2012-05-02 | 2015-03-26 | Lukas Emmenegger | Method of detecting a propellant gas |
WO2016208382A1 (en) | 2015-06-25 | 2016-12-29 | 新東工業株式会社 | Surface characteristic evaluation apparatus and surface characteristic evaluation method for steel material |
WO2017081879A1 (en) | 2015-11-09 | 2017-05-18 | 新東工業株式会社 | Steel surface characteristic evaluation method |
CN108267502A (en) | 2016-12-30 | 2018-07-10 | 大众汽车自动变速器(大连)有限公司 | The eddy detection system and detection method of case depth |
WO2019012991A1 (en) | 2017-07-10 | 2019-01-17 | 新東工業株式会社 | Surface characteristic evaluation method, surface characteristic evaluation device, and surface characteristic evaluation system |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010164483A (en) * | 2009-01-16 | 2010-07-29 | Idemitsu Eng Co Ltd | Nondestructive inspection apparatus and nondestructive inspection method |
-
2019
- 2019-03-08 JP JP2019042972A patent/JP7180461B2/en active Active
-
2020
- 2020-01-17 DE DE112020001137.2T patent/DE112020001137T5/en active Pending
- 2020-01-17 WO PCT/JP2020/001548 patent/WO2020183908A1/en active Application Filing
- 2020-01-17 US US17/434,866 patent/US11994493B2/en active Active
- 2020-01-17 CN CN202080018310.XA patent/CN113518921A/en active Pending
Patent Citations (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4528856A (en) | 1984-01-17 | 1985-07-16 | Westinghouse Electric Corp. | Eddy current stress-strain gauge |
JPH05203503A (en) | 1991-11-27 | 1993-08-10 | Toyota Motor Corp | Apparatus for measuring residual stress distribution of steel |
EP0618445A2 (en) | 1993-04-02 | 1994-10-05 | Robert Bosch Gmbh | Method and probe for non-destructive surface examination of electrically conducting materials |
JPH0792140A (en) | 1993-09-27 | 1995-04-07 | Toyota Motor Corp | Method for evaluating fatigue strength of steel member |
JP2001082911A (en) | 1999-09-14 | 2001-03-30 | Mitsubishi Heavy Ind Ltd | Component inspection apparatus |
JP2007040865A (en) | 2005-08-04 | 2007-02-15 | Ntn Corp | Nondestructive measuring method for determining depth of hardened layer, unhardened state and foreign material |
US20080001609A1 (en) | 2006-06-22 | 2008-01-03 | Takashi Kojima | Nondestructive inspection method and apparatus for a surface processed by shot peening |
JP2008002973A (en) | 2006-06-22 | 2008-01-10 | Fuji Seisakusho:Kk | Nondestructive testing method and device of shot peening treated surface |
JP2010025746A (en) | 2008-07-18 | 2010-02-04 | Toyota Motor Corp | Quenching pattern inspecting method and device |
JP2011185623A (en) | 2010-03-05 | 2011-09-22 | Toyota Central R&D Labs Inc | Device for evaluation of surface treatment |
WO2012153862A1 (en) | 2011-05-10 | 2012-11-15 | Sintokogio, Ltd. | Surface property inspection device and surface property inspection method |
EP2707705A1 (en) | 2011-05-10 | 2014-03-19 | Sintokogio, Ltd. | Surface property inspection device and surface property inspection method |
US20140084910A1 (en) | 2011-05-10 | 2014-03-27 | Sintokogio, Ltd. | Surface property inspection device and surface property inspection method |
US20150083918A1 (en) | 2012-05-02 | 2015-03-26 | Lukas Emmenegger | Method of detecting a propellant gas |
WO2016208382A1 (en) | 2015-06-25 | 2016-12-29 | 新東工業株式会社 | Surface characteristic evaluation apparatus and surface characteristic evaluation method for steel material |
US20180188209A1 (en) | 2015-06-25 | 2018-07-05 | Sintokogio, Ltd. | Surface characteristics evaluation apparatus and surface characteristics evaluation method for steel material |
WO2017081879A1 (en) | 2015-11-09 | 2017-05-18 | 新東工業株式会社 | Steel surface characteristic evaluation method |
US20180299393A1 (en) | 2015-11-09 | 2018-10-18 | Sintokogio, Ltd. | Surface characteristics evaluation method for steel material |
CN108267502A (en) | 2016-12-30 | 2018-07-10 | 大众汽车自动变速器(大连)有限公司 | The eddy detection system and detection method of case depth |
WO2019012991A1 (en) | 2017-07-10 | 2019-01-17 | 新東工業株式会社 | Surface characteristic evaluation method, surface characteristic evaluation device, and surface characteristic evaluation system |
Non-Patent Citations (8)
Title |
---|
Anonymous, "Eddy current—Wikipedia, the 4 free encyclopedia", Jul. 14, 2014, Retrieved from the Internet at URL: <https://web.archive.org/web/20140714030558/https://en.wikipedia.org/wiki/Eddy_current> retrieved on Nov. 8, 2018, 10 pages. |
Extended European Search Report for European Application No. 16863843.5 dated Nov. 22, 2018. |
International Preliminary Report on Patentability dated Sep. 23, 2021. |
International Search Report dated Mar. 31, 2020. |
International Search Report in corresponding International Application No. PCT/JP2016/066922 dated Aug. 16, 2016. |
Makino; Translation of WO 2017/081879 A1; May 18, 2017; Translated by Google & EPO (Year: 2017). * |
U.S. Final Office Action for U.S. Appl. No. 15/737,981 dated Jan. 30, 2020. |
U.S. Office Action for U.S. Appl. No. 15/737,981 dated Sep. 9, 2019. |
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